Switched power converters, such as Buck converters, can convert an input power to an output power so as to drive a load with specified voltage or current values. There are various topologies to control the converter output. In some applications, such as light emitting diode (LED) lighting applications, it may be desirable to control the average output current flowing through the LED load.
Some converters include a control loop to regulate the average output current. The control loop may include sensing circuitry to sense the average output current, an error amplifier to amplify the signal from sensing circuitry, and control logic to adjust the pulse width modulation (PWM) pulse duty cycle of the power switch. To ensure that the loop is stable, a compensation network typically is needed. Furthermore, because the loop has limited bandwidth (e.g., in the kHz range), there sometimes is a delay in the output response when there is a sudden change of input power. These factors can limit the transient response of the power converter.